I'm not a HUGE fan o silkies, but I can say a few good things about them. They are very laid back bids who get along very well with EVERYTHING, weather standard or bantam they are exelant brooders and will adopt almost any creature you put in or near their coop, and they don't make much if any noise...they just don't have the gumption to be outspoken.
I personally find cochins to be the more attractive breed softer and prettier to look at, just as laid back, just as broody and willing to adopt, they don't make much noise but when they do they are a bit louder...there are few and far between who have bad or outspoken temperments.
Both breeds fall into the feathered feet catagory which means they can get very messy, and often need some extra preening from their humans (never fun).
But all in all beauty is in the eye of the beholder, and that means that who ever their human is the birds (all breeds) will generally be something enjoyable and affectionate.
I even found that my leghorn(a breed known to be agressive) was to some degree affectionate.
